| 摘要 |
PURPOSE:To light luminous tubes efficiently and to save the labor and the time of the maintenance work, by connecting plural discharge lamps which have two luminous tubes respectively, in parallel, and providing a control means to convert to the other side lamp when the lamp current is not detected even though a power source is connected. CONSTITUTION:By turning ON a power source switch SW which is controlled by the condition that TRIACs T1 and T3 are ON, and TRIACs T2 and T4 are OFF, a capacitor C1 is charged, and the luminous tube A of the first discharge lamp 13 is lighted by the break voltage of a DIAC SS. At the next ON after the switch SW is turned OFF, a control circuit 12 controls the TRIACs and lights a luminous tube B. And in the same manner thereafter, the luminous tubes A and B repeat the lighting alternatively. When both tubes A and B are not lighted for same reason, and the lamp current is not detected by a converter 15, the circuit 12 controls and converts so as to light the luminous tubes C and D of the second discharge lamp 14. |
